package com.ruoyi.web.controller.common;

import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

@RestController
@RequestMapping("/download")
public class DownloadController {
    @PostMapping("/importTemplate")
    public void importTemplate(HttpServletResponse response) {
        //resources路径下的文件地址
        String filePath = "importTemplate/excel模板.zip";
        //用来读取resources下的文件
        Resource resource = new ClassPathResource(filePath);
        try {
            //获取文件
            File file = resource.getFile();
            // 获取文件名
            String filename = file.getName();

            // 将文件写入输入流
            FileInputStream fileInputStream = new FileInputStream(file);
            InputStream fis = new BufferedInputStream(fileInputStream);
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();

            // 清空response
            response.reset();
            // 设置response的Header
            response.setCharacterEncoding("UTF-8");
            //Content-Disposition的作用：告知浏览器以何种方式显示响应返回的文件，用浏览器打开还是以附件的形式下载到本地保存
            //attachment表示以附件方式下载   inline表示在线打开   "Content-Disposition: inline; filename=文件名.mp3"
            // filename表示文件的默认名称，因为网络传输只支持URL编码的相关支付，因此需要将文件名URL编码后进行传输,前端收到后需要反编码才能获取到真正的名称
            response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));
            // 告知浏览器文件的大小
            response.addHeader("Content-Length", "" + file.length());
            OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            outputStream.write(buffer);
            outputStream.flush();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}
